Multiple non-catalytic ADAMs are novel integrin α4 ligands

Area of Science:

• Biochemistry
• Cell Biology
• Molecular Biology

Background:

• The ADAM (a disintegrin and metalloprotease) protein family possesses both catalytic and adhesive functions.
• ADAMs are crucial for ectodomain shedding, regulating various biological processes, but their integrin ligand properties are less understood.
• A subset of human ADAMs (8 of 21) are catalytically inactive, and their roles as integrin ligands are largely unexplored.

Purpose of the Study:

• To investigate the integrin ligand properties of catalytically inactive ADAM proteins.
• To determine if non-catalytic ADAMs can mediate cell adhesion via integrin interactions.

Main Methods:

• Investigated the adhesive capabilities of specific catalytically inactive ADAM proteins.
• Utilized cell adhesion assays to assess interactions with integrin receptors.

Main Results:

• Human ADAM11, ADAM23, and ADAM29 were identified as selective ligands for integrin α4.
• Demonstrated that the disintegrin-like domains of these inactive ADAMs support integrin-dependent cell adhesion.
• This represents the first report of multiple catalytically inactive ADAMs acting as ligands for specific integrins.

Conclusions:

• Catalytically inactive ADAMs possess functional integrin ligand properties.
• These findings expand the known roles of ADAM proteins beyond ectodomain shedding.
• The study highlights a novel mechanism of cell adhesion mediated by non-catalytic ADAM-integrin interactions.